Treprostinil is a synthetic analog of prostacyclin (PGI2), indicated for the treatment of pulmonary arterial hypertension (PAH). The major pharmacologic mechanisms of action of treprostinil are direct vasodilation of pulmonary and systemic arterial vascular beds and inhibition of platelet aggregation.
U.S. Pat. No. 6,700,025 discloses a process for the stereoselective synthesis of prostacyclin derivatives, in particular for treprostinil. However, this process and other known processes involve a large number of synthesis steps and chromatographic purifications. The objective of the present invention is the discovery of a process of increased utility that involves fewer steps and chromatographic purifications as well as a highly diastereoselective resolution of a key intermediate by enzymatic means that makes the process more suitable for scale-up.